COMMUNITY FORUM

roofing materials

We need to replace our tar and gravel roof and had 2 different quotes using different materials.

#1 EPDM over new 3/8" plywood

#2 new 1/2" fiberboard, 95fs base sheet in a hot bed of asphalt at 500 degree heat using a type 2 asphalt, torch down SPS 250 granulated cap sheet to new mop down base sheet. Which is a better system? Any suggestions or comments

Both EPDM and torchdown modified are fine roof materials. The most important question to consider is that you chase down references and reputation for the installers, as well as the amt of experience they have.... Leaks in either system are generally due to incompettant installation.

I prefer the EPDM for looks and because if it ever leaks, it is easier to find and patch the problem. EPDM comes in two thicknesses. It is also possible to have it in white, if you are in ahot climate, but at higher cost.

OIne thing that concerns me about the hot mop description is that the flash point for that hot asphalt is about 500°F, meaning that if it is indeed heated to that higha temperature, there is a chance of fire in the kettle. Too much heat also makes it more likely to crystalize as it cures, which leaves it brittle and less waterproof. The proper application temp is around 420 to 470 degrees. I would double check with the person who quoted this job if he may have erred.